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Topic: Centre Hub Steered bike (Read 4159 times)

I haven't posted on this forum for ages this prject was mentioned in another thread about CNC master cylinders so I thought I would bring the bit about the Centre Hub Steered bike up to date in part because it going to a a show next week and some people showed an interest in seeing it in the metal as it where, its the Kickback show at Stoneleigh Park 1st April 2017.

Its also been featured in Performance bike Magazine in which they stated its the best special they've ever tested.

Here's some pics and more info below.

Below is an extract from an early post elsewhere

On the 3rd July last year, I ran out of excuses and had no choice but to ride the thing, the plan was to ride down our lane (about 400 yard long) feet down and get a feel for the steering etc, and also check out the brakes, gear change, etc etc, are reacting as expected, having never ridden a Centre Hub steered bike I was unsure as to what to expect, theory, geometric CAD animation and computer simulation are all very good but you don't get injured if a computer model goes haywire, Id read all sorts, vague steering!, lack of feel!, bump steer!, Quirky, all sorts. So after finally fitting the tank and seat proper (until now Id been running it on a dummy tank to set stuff up) I warmed up the engine a little donned my open face helmet so I could listen better for odd noises and get a clue as to what was going on, I pushed it out of the gate, straddled the bike, slipped it into first, and set off feet down for about 10ft, then feet up rode to the end of the lane in second gear, on the way I weaved about a bit getting a feel for the brakes and steering, braked for the lane end, turned right then left onto the main A road, I proceeded along this road for about half mile, testing the brakes and gear change where OK, I then turned right onto a windy bumpy B road which eventually swings back on itself after about a mile or so to rejoin the A road, I did 4 laps of this at speeds upto about 75mph to check engine temperatures and stuff and bed in the pads.

So what happened to the feet down plan, its simple really it just felt dead normal with no real surprises at all, in fact I've ridden strange to me bikes hundreds of times and the only stand out thing is it didn't feel odd at all, other than lack of dive under breaking, its hard to describe but it just feels really precise, After getting back and checking it over for loose stuff, oil level coolant etc, I let my mate Tony take it out, he's raced in the UK in club racing and competed in the late 80's and early 90's in both the T.T. and Manx GP on TZ's initially, and then later a Kawasaki 1100 and then GSXR's, after doing another three laps of the same A and B roads as me he came back with a big grin on his face declaring it just feels normal.

I had noticed that the front was a bit hard so backed of the compression damping a couple of notches, today I rode it again doing about 30 miles on a mixture of a A and B roads at speeds upto about 85mph, including a short stint of about 5 miles on a duel carriage way, the front damping feels about right now, handling wise its still early stages but initial impressions are very encouraging, it steers neutral, and feels very precise and is very stable, I was riding no hands today at about 70mph, just to see if the offset I build into the Hub is working as expected and it is, I even tried upsetting it by pushing one of the bars and letting go, it just holds the line you put it on, braking over bumps you can feel the suspension working, the front dips a little on first application of the brakes but then holds there, my initial setup is 40% anti dive which at this stage feels about right.

The Gen2 engine with Gen1 electrikery and Gabro's chip works great, the engine pulls really strong with good midrange, one of the main unknowns was the cooling system, home made water pump side mounted rads, however I needn't have worried it seems to be working fine, its holding a temp of between 78 and 84c during normal A and B road riding I haven't heard the fans cut in other than when its been ticking over during engine setup.

Over all it was a bit of an anti climax, I think this is a good thing, I suppose its because it feels so normal, which is much better than the opposite which involves getting thrown about and going through hedges etc......

however since then I have made a few changes, after playing with Rake Trail Ride height etc etc I now have it steering neutral in most conditions, and have the damping more or less sorted, the problem is when you make adjustments it doesn't do what you expect i.e. lifting the front makes it steer faster, which is opposite to normal, however I can now make adjustments and predict what the change will do, where as before it was confusing in part because its so adjustable and I wasn't doing it systematically, this lead to confusion and me for a time getting lost, in the end I went back to my original calculated settings and started again, but this time adjusting one thing at a time and noting the changes after a longer ride, I also stopped riding my other bikes because this was adding to the confusion.

In addition to the above:-

When most of the picture here where taken the bike was more or less straight out of the shed it had covered about a 800 miles, since its covered another 3000 or so.

This winter I have changed the front calipers to Brembo's and made a new rear suspension rocker in order to change the rising rate to a more linear setup, it felt a bit wooden at the back, and this summer I intend to try some extreme rake setting etc, as an experiment just to see what happens.

This is a very cool bike. I have wanted a FFE bike FOREVER. Did a ton of research, got the books, on the lists... I am just not to the point of where I feel comfortable with the hub centered steering part. I would love to see/read anything you have about building that part of your bike.

I once had a ride on a DiFazio hub centre steered bike. Before the ride, when he was telling me all about it, he kept saying, "feet up soon as". I pretty much do this anyway, I hate seeing riders dragging their feet, anyway it bike felt so secure and stable. Glad that yours is the same, and it really does look amazing!

I reckon me & you would get on well, or murder each other within 4hrs :-)

Your bike is amazing . . . but I know enuff about hub centre steering on 2 wheels to know that you might be ever so slightly guilty of glossing over the whole truth. £millions has been poured into developing the perfect 2wheeler & all of it ends up with the same basic problems.

I had a looong chat a few years ago with the brains behind the 'Elf Honda' project, he reckons it's greatest achievement was the one thing that is least talked about. They managed to do away with horizontal handlebars & instead used 2x levers in a vertical 'tiller' arrangement, this puts your wrists in their natural position.

Anyways. I like the way you're thinking. I like anything that is 'outside the box'.

I've only ever seen the vertical two bars (a bit like two joysticks) on Tony Foale's bikes, but I've never actually ridden one, but did toy with the idea for about five minuets, after making a mockup I came to the conclusion that it felt very odd and less controllable than normal bars, also it relied on wrist strength, where as normal bars use shoulders which are much stronger, It could also be the fact I've been using handle bars for nearly 40 years that persuaded me to go this route.

I didn't build a Centre Hub bike because I think forks are wrong, I did it out of curiosity, Forks have inherent but have had well over 50 years of development by every motorcycle manufacturer on the planet and millions spent on solving these problems, Centre Hub systems also have problems however they have had far less time and money spent developing them, I wanted to see for myself what it was all about and thought the best way was to build one, I now know a lot more about what is required and the failings of both, I've yet to come to a conclusion as to which is better, there are good and bad point in both systems, my next project may well go a different route perhaps a Hossack type setup but wit my take on it, and probably a V4 engine.

I seem to remember reading about the ELF GP bikes, that their only real failing was the front swinging arm, which had to be wide to achieve the minimum steering lock, only had to kiss the tarmac and the rider was on his ear. A lot less forgiving than the "normal" set up.My final year project at college was titled "Motorcycle Suspension". It detailed a Hossack/Fior type set up. Just afterwards BMW introduced a very similar set up! Never mind.....Best of luckcheersBill

I didn't build a Centre Hub bike because I think forks are wrong, I did it out of curiosity, Forks have inherent but have had well over 50 years of development by every motorcycle manufacturer on the planet and millions spent on solving these problems, Centre Hub systems also have problems however they have had far less time and money spent developing them, I wanted to see for myself what it was all about and thought the best way was to build one, I now know a lot more about what is required and the failings of both, I've yet to come to a conclusion as to which is better, there are good and bad point in both systems, my next project may well go a different route perhaps a Hossack type setup but wit my take on it, and probably a V4 engine.

Cheers

Shaun.

Telescopic forks are wrong.

If you put 10x engineers in a room to invent the motorcycle, then the one that suggest's telescopic forks to hold the front wheel would first be ridiculed, then thrown out the window.

This bike grabbed my attention. Very out of the box thinking yet still retaining a strong link with the UJM.

My view on the above is it depends on what the bike is intended to be used for, modern forked bikes are remarkably good at most things, and its what we are used to, and some of its so called weird characteristics are useful, but the forks are only part of it, we could get into wheel paths, stable rake and trail under breaking etc etc etc, it could turn into and endless debate, but at present in every form of motorbike racing that I know of forks are it, that's not to say it wont change in the future, it probably depends more on marketing than engineering, I find most bikers are pretty conservative and prefer what they know, if a major manufacturer started racing an FFE bike and won with it things could change fast, but with Control tyres prevalent in most racing its unlikely because Tele forked bikes tyres aren't ideally suited to FFE bikes because they don't work the tyre as hard and consequently require softer tyres.

As for the motomorphic, Not for me, having said that I know some people hate my bike, but I didn't build it for them I built it for me for the reasons already stated.

A an aside I've also been playing with Steer by wire, and it shows some promise, this uses haptic feedback and totally eliminates bump steer etc etc, now this really is a can of worms in the making.

Your'e obviously upset, however PM me you are welcome to come ride it, as are your mates, or you could buy the magazine as mentioned above and read about it, and no I havn't heard of em!, having said they probably havn't heard of me either, but why would they? I'm just a normal bloke with a PC and some obselete machinery, who happens to like maths and motorbikes, anyway I have nothing to hide.

I've edited this to add, I have heard of Andy Stevens if fact he contacted me recently to make a water pump housing, like the one below for his bike project, which I think looks very good.

Apparently, he just wheeled it out of the shed, lit the fires & kicked the tyres & all was beautifully awesome. Where have we heard all of that before . . .

Time rich & £cash rich. Knows all about the info that's bandied about on t'internets, but knows now't about the real garage inventors.

He's never heard of 'Andy Stevens', Shig, Stu or even Sid & myself, yet he worships the false icon of some con artist called Hossack.

Does the bike handle? No, I don't think it does.

Guys... Play nicely please.

CHA5, are you a bike builder? I ask not because I am looking to call people out, but I am genuinely curious. As someone who likes to check out peoples customs, I am always looking to see more. I am not familiar with any of the names you listed. I would like to see what they (and you) are building.

Not being into bikes as much as a few on here i am thoroughly enjoying this thread due to your build, passion and thought skills being applied to your project this is exactly what our forum is for.

Brought back memories looking at your ally tank being built, in the late 70ies I used to moonlight while an apprentice to a specialty tank builder in Erith we made replicas ally tanks from scratch for Ducati, Bmw and the like, I wish i would of stayed with that old man I would be a millionaire now.